There are many structures that take the form of an outer shell of material supported by a support framework, such as aircraft fuselages, aircraft wings, ship hulls, submarines, pontoons, blimps, and the like. Some of these structures are typically formed by joining together multiple structural sub-sections (hereinafter, referred to as “hull sections”) to form a whole structure. These hull sections must be joined together with high structural integrity. In many applications, the completed structure must maintain pressure integrity once assembled.
Commonly, the hull sections are joined to a bulkhead located at each seam. Each hull section is fastened to the bulkhead with numerous equally-spaced fasteners, such as rivets or screws, which are driven through the outer shell and into the rigid bulkhead located beneath. There are several problems with this method for joining the hull sections, however. First, it can be very time consuming to insert and fix the large number of fasteners required. Second, the fasteners often project above the outer surface of the shell and therefore, can perturb fluid flow along the outer surface. This is especially particularly undesirable in the case of a vessel hull, aircraft fuselage, aircraft wing, or the like. Third, the strength of each fastener is limited due to the small contact area typically associated with each fastener head. Fourth, localized fastener stress can cause weak joints and potential pressure leaks due to distortion of the outer shell. Finally, the alignment accuracy and run-out associated with this fastening technique is generally poor.
A need exists, therefore, for a fastening system that avoids at least some of the drawbacks of the prior-art.